JP5841265B2 - Wheel control device, vehicle, wheel control method - Google Patents

Description

  The present invention relates to a technique for controlling a plurality of wheels provided in a vehicle.

  Patent Document 1 below discloses a technique for controlling a motor incorporated in each wheel of a vehicle. According to this technique, when a change in the pitch rate of the vehicle (a change in the attitude of the vehicle) is detected, the driving force of one of the front wheels or the rear wheels is reduced, and the reduced driving force is reduced to the other. Pitch control to be applied to the wheels is executed.

JP 2007-118898 A

  The pitch control disclosed in Patent Document 1 relates to torque control of a motor that drives each of the front wheels and the rear wheels while having the possibility of reducing the pitch rate of the vehicle when the vehicle passes a step on the road surface. When the torque distribution of each motor is controlled in order to optimize the vehicle motion, a phenomenon may occur in which the signs of the front wheel motor torque and the rear wheel motor torque are reversed. For example, torque distribution may generate torque in a driving direction (powering direction) in a predetermined motor, while torque in a braking direction (regeneration direction) opposite to the driving direction may be generated in another motor. In such a case, for example, in one motor, since the sign of the torque is reversed in the process of reducing the distribution torque from the reference torque, it is known that the phase is changed from the phase in which the electric loss of the motor decreases to the phase in which the motor increases. . As a result, there is a risk that electric loss in the entire motor increases and power consumption increases as compared with the case where torque distribution is not controlled. Therefore, in designing this type of motor capable of independently driving a plurality of wheels, a technique for suppressing an increase in power consumption related to torque distribution control is required.

  The present invention has been made in view of the above points, and one of its purposes is to provide each motor in a vehicle including a plurality of motors capable of independently driving a plurality of wheels provided in the vehicle. The present invention is to provide a technique effective in appropriately controlling vehicle motion by the torque distribution and suppressing an increase in power consumption related to the control.

  In order to achieve the above object, a wheel control device according to the present invention is a device that controls a plurality of wheels provided in a vehicle, and includes at least a control unit. This control unit fulfills a function of setting a predetermined reference torque for each of the plurality of motors according to the first information related to the input operation by the driver. The corresponding motor can be controlled based on the set reference torque. In addition, the control unit includes a distributed torque limit mode. In this distributed torque limit mode, one or a plurality of first motors among a plurality of motors are controlled by a torque obtained by adding and distributing the first distributed torque to the reference torque in accordance with the second information relating to the motion state of the vehicle. In addition, one or a plurality of second motors different from the first motor are controlled by the torque obtained by subtracting and distributing the second distribution torque from the reference torque, and the torque of each of the first motor and the second motor is controlled. The first distribution torque and the second distribution torque are limited so that the action direction of the change does not change before and after the addition distribution and the subtraction distribution. That is, the control unit has a function as a means for setting or calculating a predetermined reference torque, and a function as a means for controlling the first motor and the second motor while limiting the first distribution torque and the second distribution torque. Fulfill. In this case, the first distribution torque and the second distribution torque may be the same magnitude or different magnitudes. In addition, the plurality of motors may be configured by only one first motor and one second motor, or may be configured by the same number of first motors and two second motors. For the detection of the first information and the second information, it is preferable to use one or a plurality of sensors provided in the vehicle in order to detect the respective information.

  According to the wheel control device configured as described above, in both the first motor and the second motor, the direction of the torque change between the driving direction (power running direction) and the braking direction (regenerative direction) before and after torque distribution. Is prevented. That is, the sign of torque is prevented from changing. For example, in the second motor, since the sign of the torque is prevented from being reversed in the process of reducing the second distribution torque from the reference torque, the phase in which the electric loss of the motor decreases can be switched to the increase phase. Absent. As a result, it is possible to suppress an increase in power consumption due to an increase in electrical loss in the entire motor. Therefore, it is possible to suppress an increase in power consumption related to the control while appropriately controlling the vehicle motion.

  In the wheel control device according to the present invention, in the distributed torque limit mode, the control unit has a case where the magnitude of at least one of the first distributed torque and the second distributed torque exceeds the reference torque. In addition, it is preferable to limit the distribution torque so that the distribution torque is equal to or less than the reference torque. In this case, by selecting the magnitude of the distributed torque within a predetermined range in accordance with the magnitude of the reference torque, it is possible to reliably prevent changes in the direction of torque action for each of the first motor and the second motor. it can.

  In the wheel control device according to the present invention, in the distributed torque limit mode, the control unit has a case where the magnitude of at least one of the first distributed torque and the second distributed torque exceeds the reference torque. In addition, it is preferable to limit the distribution torque so that the magnitude of the distribution torque matches the magnitude of the reference torque. In this case, by simply selecting the magnitude of the distribution torque according to the magnitude of the reference torque, it is possible to reliably prevent the change in the direction of the torque applied to each of the first motor and the second motor.

  In the wheel control device according to the present invention, the plurality of motors includes one first motor incorporated in one of the left wheel and the right wheel corresponding to each other, and the other of the left wheel and the right wheel. It is preferable to be constituted by only one second motor incorporated in the. In this case, it is preferable that the control unit sets the first distribution torque related to one first motor and the second distribution torque related to one second motor to the same magnitude. As a result, a change in the driving torque of at least the two wheels before and after the torque distribution is suppressed, and control without causing a sense of incongruity to the vehicle occupant becomes possible.

  In the wheel control device according to the present invention, the plurality of motors include two first motors incorporated in two of the four wheels as a plurality of wheels, and two wheels other than the two wheels. It is preferable that it is constituted by only two second motors incorporated in each of the above. In this case, it is preferable that the control unit sets the first distribution torque for each of the two first motors and the second distribution torque for each of the two second motors to the same magnitude. As a result, the change of the driving torque of the four wheels before and after the torque distribution is suppressed, and control without giving a sense of incongruity to the vehicle occupant becomes possible.

  In the above-described wheel control device according to the present invention, it is preferable that the second information includes first motion information related to the rolling motion or pitching motion of the vehicle and second motion information related to the yaw motion of the vehicle. In this case, the control unit sets the first distribution torque and the second distribution torque according to the first movement information, and the roll movement control or the pitching movement control, and the first distribution according to the second movement information. One of the control and the yaw motion control for setting the torque and the second distribution torque is selectively executed, and the distribution torque limit mode is selected when the roll motion control or the pitching motion control is executed. On the other hand, it is preferable not to select the distributed torque limit mode when executing the yaw motion control. In short, with regard to the priority for limiting the distribution torque, the pitching motion control or roll motion control related to the ride comfort of the vehicle occupant is more relevant than the yaw motion control related to the vehicle steering stability. Is set higher. As a result, it is possible to suppress an increase in power consumption related to the control while appropriately controlling the vehicle motion so as not to impair the steering stability of the vehicle as much as possible while sacrificing the ride comfort of the vehicle occupant. Become.

  In the wheel control device according to the present invention, in the distributed torque limiting mode, the control unit limits the first distributed torque and the second distributed torque when it is not necessary to reduce power consumption in a plurality of motors. Preferably not. This makes it possible to select whether or not to limit the distribution torque in accordance with an appropriate request, and is reasonable.

In the wheel control device according to the present invention, in the power storage device mounted on the vehicle as a drive source for the plurality of motors, the control unit has a ratio of the remaining charge to the power storage capacity at the time of full charge exceeds a predetermined threshold. In such a case, it is preferable to determine that it is not necessary to reduce power consumption in a plurality of motors. In this case, examples of the power storage device include a battery and a capacitor. The predetermined threshold value may be a constant value set in advance, or may be a variable value whose setting can be changed according to the state of vehicle motion or the like. This makes it possible to select whether or not to limit the distribution torque in accordance with a request from the power storage device side, which is reasonable.

  A vehicle according to the present invention includes a plurality of wheels, a plurality of motors that can independently drive each of the plurality of wheels, and a motor control device that controls the plurality of motors. It is comprised by the said wheel control apparatus. Accordingly, it is possible to realize a vehicle having a configuration capable of appropriately suppressing vehicle movement and suppressing an increase in power consumption related to the control.

  A wheel control method according to the present invention is a method for controlling a plurality of wheels provided in a vehicle, and relates to an input operation by a driver for torque control of a plurality of motors capable of independently driving the plurality of wheels. A step of setting a predetermined reference torque for each of the plurality of motors according to the information of 1, and a step of using a distributed torque limit mode. This wheel control method can also include still another step. In the distribution torque limit mode, one or a plurality of first motors among a plurality of motors are controlled with a torque obtained by adding and distributing the first distribution torque to the reference torque according to the second information relating to the motion state of the vehicle. In addition, one or a plurality of second motors different from the first motor are controlled by a torque obtained by subtracting the second distribution torque from the reference torque, and the torque of each of the first motor and the second motor is controlled. The first distribution torque and the second distribution torque are limited so that the direction of action does not change before and after the addition distribution and the subtraction distribution. Thus, in both the first motor and the second motor, the direction of the torque is prevented from changing between the driving direction (power running direction) and the braking direction (regenerative direction) before and after torque distribution. That is, the sign of torque is prevented from changing. As a result, it is possible to suppress an increase in power consumption due to an increase in electrical loss in the entire motor. Therefore, it is possible to suppress an increase in power consumption related to the control while appropriately controlling the vehicle motion.

FIG. 1 is a diagram showing a schematic configuration of a drive mechanism of a vehicle 10 according to the present invention. FIG. 2 is a diagram showing a schematic configuration of the control unit 30 in FIG. Figure 3 is a diagram depicting a processing flow of the mode Tatoruku control. FIG. 4 is a diagram illustrating a case where the motor is in the distributed torque limit mode in the motor torque control of FIG. 3 in the relationship between the motor torque and the electrical loss. FIG. 5 is a diagram for explaining a case where the distribution torque limit mode is not established in the motor torque control of FIG. 3 in the relationship between the motor torque and the electrical loss. FIG. 6 is a diagram illustrating the roll motion control in the vehicle 10 in FIG. FIG. 7 is a diagram illustrating pitching motion control in the vehicle 10 in FIG. FIG. 8 is a diagram for explaining yaw motion control in the vehicle 10 in FIG.

  Hereinafter, the vehicle 10 which is one Embodiment of this invention is demonstrated using drawing.

  FIG. 1 is referred to for the schematic configuration of the drive mechanism of the vehicle 10. An arrow F in FIG. 1 indicates the forward direction of the vehicle 10, and an arrow R indicates the reverse direction of the vehicle 10. Further, the arrow D1 in FIG. 1 indicates the left-right direction of the vehicle 10, and the arrow D2 indicates the front-rear direction of the vehicle 10. The vehicle 10 corresponds to a “vehicle” of the present invention, and includes left and right front wheels 11 and 12 and left and right rear wheels 13 and 14 as wheels. The left and right front wheels 11, 12 are supported by a vehicle body 10 a as a spring on the vehicle 10 via suspension mechanisms 15, 16 independently of each other. The left and right rear wheels 13 and 14 are supported on the vehicle body 10a of the vehicle 10 via suspension mechanisms 17 and 18 respectively or independently of each other.

  Electric motors 19 and 20 are incorporated in the left and right front wheels 11 and 12, respectively, and each of the motors 19 and 20 functions to transmit torque to the corresponding wheel. Similarly, motors 21 and 22 are incorporated in the left and right rear wheels 13 and 14, respectively, and the motor motors 21 and 22 each function to transmit torque to the corresponding wheels. The motors 19 to 22 are so-called in-wheel motors, and are disposed under the spring of the vehicle 10 together with the left and right front wheels 11 and 12 and the left and right rear wheels 13 and 14. And each motor 19-22 is controlled independently, respectively, and each of the left-right front wheels 11 and 12 and the right-and-left rear wheels 13 and 14 is made to drive direction (it is also called a "power running direction") or a braking direction ("regenerative direction"). The driving torque for driving is also controlled.

  These motors 19 to 22 are all configured as AC synchronous motors, for example. In this case, the DC power of the power storage device 24 (such as a battery or a capacitor) mounted on the vehicle 10 as a drive source is converted into AC power via the inverter 23, and the AC power is supplied to each motor. Each motor is driven to apply driving torque in the driving direction or braking direction to the left and right front wheels 11 and 12 and the left and right rear wheels 13 and 14. In addition, these motors 19 to 22 can be regeneratively controlled using the rotational energy of the left and right front wheels 11 and 12 and the left and right rear wheels 13 and 14. Each of the four motors 19 to 22 may have a structure directly connected to a corresponding wheel, or may have a configuration in which a speed reducer is interposed between the corresponding wheels.

  Brake mechanisms 25, 26, 27, and 28 are provided between the four wheels 11 to 14 and the corresponding four motors 19 to 22, respectively. Each of the brake mechanisms 25 to 28 is configured as a known braking device such as a disc brake or a drum brake. The brake mechanisms 25 to 28 are, for example, brake actuators 29 that actuate brake caliper pistons that generate braking force on the wheels 11 to 14 and brake shoes (both not shown) by hydraulic pressure from a master cylinder (not shown). It is connected to the. The inverter 23 and the brake actuator 29 are each connected to the control unit 30.

  In the vehicle 10 described above, each of the two left and right front wheels 11 and 12 is provided in addition to a configuration in which each of the four wheels 11 to 14 is driven by each of the four motors 19 to 22 (that is, a four-wheel motor vehicle). A configuration in which each of the two motors 19 and 20 is driven (that is, a front-wheel-drive two-wheel motor vehicle), and a configuration in which each of the two left and right rear wheels 13 and 14 is driven by each of the two motors 21 and 22 (that is, A rear-wheel drive two-wheel motor vehicle can also be employed.

  A first detection sensor 31, a second detection sensor 32, and a third detection sensor 33 are connected to the control unit 30, and output signals from various sensors including the first to third detection sensors 31 to 33 are output from the control unit 30, respectively. Input to the control unit 30. The first detection sensor 31 is configured as a detection sensor (operation state detection means) for detecting an operation state operated by the driver for driving the vehicle 10. The second detection sensor 32 is configured as a detection sensor (motion state detection means) for detecting the motion state generated in the vehicle body 10a (on the spring) of the vehicle 10 during traveling. The third detection sensor 33 is configured as a detection sensor (disturbance detection means) for detecting a disturbance acting on the vehicle 10 during traveling.

  As the first detection sensor 31, for example, a steering angle sensor that detects a driver's operation amount (steering angle) with respect to a steering wheel (not shown) for steering a vehicle, or a driver's operation amount (depression) with respect to an accelerator pedal (not shown). An accelerator sensor that detects the amount, angle, pressure, etc.), a throttle sensor that is provided in an engine (not shown) and detects the opening of a throttle that operates according to the operation of the accelerator pedal, and an operation for a brake pedal (not shown) Brake sensor that detects the amount of operation (depression, angle, pressure, etc.) by the user, parking brake sensor that detects the on / off state of the parking brake (not shown), and on / off state of the ignition (not shown) An ignition sensor that detects the state of charge of the power storage device 24. And the like.

  As the second detection sensor 32, for example, a sprung vertical acceleration sensor that detects vertical acceleration in the vertical direction of the vehicle body 10 a (sprung), a vehicle speed sensor that detects the vehicle speed of the vehicle 10, and a yaw rate generated in the vehicle 10 are detected. Examples include a yaw rate sensor, a pitch rate sensor that detects a pitch rate generated in the vehicle 10, and a roll rate sensor that detects a roll rate generated in the vehicle 10.

  As the third detection sensor 33, for example, a stroke sensor that detects the respective stroke amounts of the suspension mechanisms 15 to 18, or an unsprung vertical acceleration sensor that detects vertical acceleration in the vertical direction below the spring of the vehicle 10 including the wheels 11 to 14. Etc.

  The control unit 30 outputs a control signal for controlling the motors 19 to 22 to the inverter 23 on the basis of output signals from various sensors including the first to third detection sensors 31 to 33, and also outputs to the brake actuator 29. It fulfills the function of outputting a control signal for controlling the brake mechanisms 25-28. As a result, the control unit 30 can grasp and control the traveling state of the vehicle 10 and the behavior of the vehicle body 10a. The control unit 30 includes a microcomputer including a CPU, a ROM, a RAM, and the like as main components, and executes various programs. The control unit 30 constructs a wheel control device that controls the four wheels 11 to 14 provided in the vehicle 10 and controls the four motors 19 to 22, and is the “wheel control device” of the present invention. And “motor control device”.

  Specifically, with respect to the control of the traveling state of the vehicle 10, the control unit 30 performs this operation when the driver is operating the accelerator pedal based on the output signal output from the first detection sensor 31, for example. The required drive torque (required drive force) corresponding to the accompanying accelerator operation amount, that is, the drive torque (drive force) to be generated by each of the motors 19 to 22 in order to drive the vehicle 10 can be calculated. Further, based on the output signal output from the first detection sensor 31, the control unit 30, for example, when the driver is operating the brake pedal, the required braking torque (requested) according to the amount of brake operation associated with this operation. Braking force), that is, the required braking torque (braking force) to be generated by the motors 19 to 22 and the brake mechanisms 25 to 28 in order to decelerate the vehicle 10 can be calculated. And the control unit 30 is a signal input from the inverter 23, specifically, a signal indicating the amount of electric power or current supplied to each of the motors 19 to 22 at the time of power running control, or the motor 19 to 22 at the time of regenerative control. Based on the signals representing the electric energy and the current value regenerated from each of the motors, the motors 19 to 22 are controlled so that the output torque of each of the motors 19 to 22 follows the desired required braking torque or the required braking torque.

  The control unit 30 appropriately controls the distribution of the torque generated by each of the in-wheel motors 19 to 22, thereby causing the vehicle 10 to travel and roll motion and pitching as behavior generated on the vehicle body 10a (on the spring). Control movement and yaw movement. For this reason, as shown in FIG. 2, the control unit 30 includes an input unit 41 as an input unit, a vehicle body behavior control command value calculation unit 42 as a vehicle body behavior control value calculation unit, and a driving force distribution as a driving force distribution calculation unit. A calculation unit 43, a torque calculation unit 44 as a torque calculation means, and an output unit 45 are provided.

  Signals are input from the first detection sensor 31, the second detection sensor 32, and the third detection sensor 33 to the input unit 41. Based on the input signal from the first detection sensor 31, the input unit 41, for example, the steering angle of the steering wheel by the driver, the accelerator operation amount and throttle opening accompanying the operation of the accelerator pedal, and the operation of the brake pedal The brake operation amount, the ignition on / off state, the state of charge of the power storage device 24, and the like are acquired. Further, the input unit 41 acquires, for example, the vehicle speed of the vehicle 10, the roll rate, the pitch rate, the yaw rate, and the like of the vehicle body 10a based on the input signal from the second detection sensor 32. Further, the input unit 41 acquires, for example, the size of the unevenness of the road surface on which the vehicle 10 is traveling, the size of the influence of the cross wind on the vehicle 10, based on the input signal from the third detection sensor 33. Thus, the input unit 41 outputs the acquired various detection values to the vehicle body behavior control command value calculation unit 42.

  The vehicle body behavior control command value calculation unit 42 calculates a target longitudinal driving force as a control command value for running the vehicle 10 using the various detection values from the input unit 41, and also displays the behavior generated in the vehicle body 10a. It fulfills the function of calculating control command values (target roll moment, target pitch moment and target yaw moment) for control. The vehicle body behavior control command value calculation unit 42 outputs the command values representing the calculated target longitudinal driving force, target roll moment, target pitch moment, and target yaw moment to the driving force distribution calculation unit 43.

  The driving force distribution calculating unit 43 distributes the target longitudinal driving force, the target roll moment, the target pitch moment, and the target yaw moment to the wheels 11 to 14 based on the command value from the vehicle body behavior control command value calculating unit 42. It fulfills the function of calculating each driving force to be generated. The driving force distribution calculating unit 43 outputs the calculated driving forces to the torque calculating unit 44.

The torque calculation unit 44 functions to calculate the torque that should be generated by each of the motors 19 to 22 corresponding to each driving force calculated by the driving force distribution calculation unit 43. For example, in the torque calculation unit 44, the same reference torque (reference reference to be described later) is set for each of the four motors 19 to 22 in accordance with an input signal from the first detection sensor 31, for example, first information related to an input operation by the driver. Torque T ₀ ) is set. In this case, four times the reference torque matches the torque required for the four motors 19 to 22 as a whole. Further, the torque calculator 44 distributes the reference torque to the reference torque (described later) according to the input signal from the second detection sensor 32, for example, the second information regarding the motion state (roll motion, pitch motion and yaw motion) of the vehicle 10. Torque to which the distributed torque ΔT) is distributed is calculated. Then, the torque calculation unit 44 outputs the calculated torque to the output unit 45. In this case, the torque calculation unit 44 has a function of substantially performing torque control of the motors 19 to 22 capable of independently driving the four wheels 11 to 14, and the “control unit” of the present invention is used. Configure.

  The output unit 45 outputs a drive signal corresponding to the torque calculated by the torque calculation unit 44 to the inverter 23. As a result, the inverter 23 controls the drive power (drive current) supplied to the motors 19 to 22 to drive the motors 19 to 22. As a result, driving torque is generated in each of the wheels 11 to 14. As a result, the vehicle 10 can be appropriately traveled according to the operation state by the driver, and the roll motion, pitch motion, and yaw motion in the vehicle body 10a can be appropriately controlled.

  The present embodiment is characterized in that the motor torque control shown in FIG. 3 is used particularly when the torque to be generated by each of the two motors 19 and 20 is calculated by the torque calculation unit 44 described above. This motor torque control is a control for generating an appropriate torque for each of the two motors 19 and 20 corresponding to each other in the left-right direction of the vehicle 10 (the direction of the arrow D1 in FIG. 1). The process from step S101 to step S108 is included. The motor torque control is executed by the control unit 30 that substantially includes the torque calculation unit 44. This motor torque control is included in the “wheel control method” of the present invention.

  In the process of step S101, it is determined whether or not the vehicle 10 is traveling. For this determination, the first detection sensor 31 or the second detection sensor 32 can be used. For example, when the parking brake is on by the parking brake sensor as the first detection sensor 31 or when the ignition is on by the ignition sensor, the vehicle speed is detected by the vehicle speed sensor as the second detection sensor 32. The vehicle 10 is determined to be traveling. When it is determined that the vehicle 10 is traveling (Yes in step S101), the process proceeds to step S102. On the other hand, when it is determined that the vehicle 10 is not traveling (in the case of No in step S101), the motor torque control is terminated as it is.

  In the process of step S102, it is determined whether or not to execute the torque distribution process. When the torque distribution process is executed (Yes in step S102), the process proceeds to step S103, while when the torque distribution process is not executed (No in step S102), the process proceeds to step S104.

In the process of step S103, the initial distribution torque ΔT (≧ 0) used for the torque distribution process is calculated, and the process proceeds to step S105. This distribution torque ΔT is set to perform torque distribution with respect to a predetermined reference torque T ₀ for each of the two motors 19 and 20. In this case, the initial distribution torque ΔT is set based on information detected by at least one of the first detection sensor 31 and the second detection sensor 32, for example. Further, the distribution torque ΔT may be the same value for the two motors 19 and 20, or may be a different value for each motor. On the other hand, this initial distribution torque ΔT may be a predetermined constant value.

  In the process of step S104, since it is determined not to execute the torque distribution process, the distribution torque ΔT is set to zero and the process proceeds to step S108.

In the process of step S105, it is compared with the absolute value magnitude of the distribution torque ΔT computed the reference torque T ₀ in step S103 (i.e., the magnitude of the reference torque T _0). If the magnitude of the distribution torque ΔT exceeds the absolute value of the reference torque T ₀ (Yes in step S105), the process proceeds to step S105. On the other hand, when the magnitude of the distribution torque ΔT is equal to or smaller than the absolute value of the reference torque T ₀ (No in step S105), the process proceeds to step S108.

  In the process of step S106, the necessity of power reduction for suppressing power consumption is determined. Typically, for example, information related to the SOC (state of charge) of the power storage device 24 is acquired by the power storage sensor as the second detection sensor 32, and this acquired information is used to determine the necessity of power reduction. In this case, the power storage device 24 corresponds to the “power storage device” of the present invention. Here, “SOC” is a unit indicating the state of charge, and indicates the ratio (percentage) of the remaining charge with respect to the storage capacity at the time of full charge. When the obtained SOC is below a predetermined threshold value set in advance, it is determined that power reduction is necessary because the ratio of the remaining charge is relatively low, and step S107 for limiting the distribution torque ΔT is determined. Proceed. On the other hand, when the obtained SOC exceeds a predetermined threshold value set in advance, the ratio of the remaining charge is relatively high, so it is determined that power reduction is unnecessary, and the distribution torque ΔT is limited. Step S107 is skipped and the process proceeds to Step S108. That is, the distribution torque ΔT is not limited when it is not necessary to reduce power consumption. This makes it possible to select whether or not to limit the distribution torque in accordance with an appropriate request from the power storage device 24 or the like, which is reasonable. The predetermined threshold value may be a preset constant value, or may be a variable value that can be changed according to the state of vehicle motion. If the necessity for power reduction is not determined, step S106 can be omitted.

In the process of step S107, it is set as the size of the distribution torque ΔT matches the size of the reference torque T _0. Thus, if the size of the distribution torque ΔT exceeds the absolute value of the reference torque T ₀ is, by matching the size of the distribution torque ΔT to the magnitude of the reference torque T _0, to limit the distribution torque ΔT be able to. That is, this step S107 is an effective process when power reduction is necessary. In this case, by simply selecting the magnitude of the distribution torque ΔT according to the magnitude of the reference torque T ₀ , it is possible to reliably prevent a change in the direction of torque applied to each of the motors 19 and 20. In the process of step S107, in addition to limiting the magnitude of the distribution torque ΔT so as to match the magnitude of the reference torque T ₀ , the magnitude of the distribution torque ΔT is made smaller than the magnitude of the reference torque T _0. It can also be limited to. That is, it is only necessary that the magnitude of the distribution torque ΔT can be limited to the magnitude of the reference torque T ₀ or less. In this case, by selecting the magnitude of the distribution torque ΔT within a predetermined range in accordance with the magnitude of the reference torque T ₀ , it is possible to reliably prevent changes in the direction of torque applied to each of the motors 19 and 20. it can.

In the process of step S108, the torque _{T L} of the motor 19 of the left front wheel 11, and re-setting by relative to the reference torque _{T 0} is added allocate distribution torque [Delta] T, also the torque _{T R} of the motor 20 of the right front wheel 12, Reset is performed by subtracting and distributing the distribution torque ΔT with respect to the reference torque T ₀ . Thereby, for the motor 19 of the left front wheel 11, a drive signal corresponding to the reset torque _TL is output from the torque calculation unit 44 to the inverter 23 via the output unit 45, and for the motor 20 of the right front wheel 12 the drive signal corresponding to the torque T _R that is reset is output from the torque calculation unit 44 to the inverter 23 via the output unit 45. On the other hand, both the motor 22 of the motor 21 and the right rear wheel 14 of the left rear wheel 13, a driving signal corresponding to the reference torque T ₀ is output to the inverter 23 via the output unit 45 from the torque computing unit 44 . And after the process of step S108 is complete | finished, it returns to step S101 again.

According to the process from step S105 to step S108, motor torque distributed adding distribution torque [Delta] T (first distribution torque) with respect to the reference torque T ₀ in accordance with the second information on the motion state of the vehicle 10 19 (first motor) is controlled, and a motor 20 (second motor) different from the motor 19 is controlled with a torque obtained by subtracting and distributing the distribution torque ΔT (second distribution torque) from the reference torque T ₀ . For each of the motors 19 and 20, a distribution torque limiting mode is formed in which the distribution torque is limited so that the direction of the torque operation does not change before and after the addition distribution and the subtraction distribution. 4 and 5 are referred to for the operation and effect of the distributed torque limit mode.

  Here, in each of the motors 19 and 20, torque proportional to the current is generated. On the other hand, the electrical loss in the motor is defined by the inverter loss proportional to the current and the motor loss proportional to the square of the current. The characteristic that it is done is known. Therefore, for the relationship between the motor torque (proportional to the current) and the electrical loss, reference is made to the curve L having a sharp convex portion shown in FIGS.

FIG. 4 shows the electrical loss when the distribution torque ΔT is limited by the motor torque control in FIG. 3 so that the magnitude of the distribution torque does not exceed the absolute value of the reference torque T ₀ . In this case, the motor 19 of the left front wheel 11, by the torque increases ΔT min from the reference torque T ₀ to T _L, the electrical loss may increase on the curve L from the reference loss P ₀ to P _L. On the other hand, in the motor 20 of the right front wheel 12, by the torque reduction ΔT min and to T _R from the reference torque T _0, electrical losses on curves L from the reference loss P ₀ drops to P _R. As a result, the electrical losses across the motors 19 and 20 increases ΔP min from the reference loss _{P 0} to a final loss _P 1 (average value of _{P L} and _{P R).}

On the other hand, FIG. 5 shows the electrical loss when the magnitude of the distribution torque ΔT exceeds the absolute value of the reference torque T ₀ . In this case, the motor 19 of the left front wheel 11, by increasing ΔT min to T _L from the reference torque T ₀ torque as in the case of FIG. 4, the electrical losses from the reference loss P ₀ on the curve L P _Ascend to _L. However, the motor 20 of the right front wheel 12, unlike the case of FIG. 4, when the torque is reduced ΔT min from the reference torque T ₀ to T _R, a phenomenon that the sign of the torque is reversed occurs. In this case, the electrical loss is increased from the reference loss P ₀ to P _R after temporarily lowering the upper curve L. That is, the phase is changed from the phase in which the electrical loss of the motor 20 decreases to the phase in which it increases. As a result, the magnitude of ΔP, which is an increase in electrical loss in the motors 19 and 20 as a whole, exceeds the magnitude of ΔP in the case of FIG. That is, in the case of FIG. 5, the electrical loss is larger than in the case of FIG.

Therefore, referring to FIG. 4 and FIG. 5, by restricting the distribution torque ΔT by the motor torque control in FIG. 3, in both the motors 19 and 20, the direction of the torque acting before and after the torque distribution is the driving direction. A change between the (power running direction) and the braking direction (regeneration direction) is prevented. That is, the sign of torque is prevented from changing. In particular, in the motor 20, since the sign of the torque is prevented from being reversed in the process of reducing the distribution torque ΔT from the reference torque T ₀ , the motor 20 can be switched from the phase in which the electric loss of the motor is reduced to the phase in which it is increased. Absent. As a result, it is possible to suppress an increase in power consumption due to an increase in electrical loss in the motors 19 and 20 as a whole. Therefore, it is possible to suppress an increase in power consumption related to the control while appropriately controlling the vehicle motion.

  Further, according to the present embodiment, since the distribution torque regarding the motors 19 and 20 is set to the distribution torque ΔT having the same magnitude, the driving torque of at least the two wheels in total changes before and after the torque distribution. Is suppressed, and control without giving a sense of incongruity to the vehicle occupant becomes possible. In addition, since torque distribution is not implemented about the other motors 21 and 22, it cannot be overemphasized that the drive torque in four wheels total changes before and after torque distribution.

  The present invention is not limited to the above exemplary embodiment, and various applications and modifications are possible. For example, each of the following embodiments to which the above embodiment is applied can be implemented.

  In the motor torque control of FIG. 3, the case where the above-described distributed torque limit mode is executed only for the two motors 19 and 20 related to the two left and right front wheels 11 and 12 among the four motors 19 to 22 has been described. The distributed torque limit mode is executed only for the two motors 21 and 22 related to the left and right rear wheels 13 and 14, or the distributed torque limit mode is executed for the four motors 19 to 22 related to all the wheels 11 to 14. In this case, the present invention can also be applied.

When the distributed torque limit mode is executed for the four motors 19 to 22, the two motors selected according to the state of the driving motion (typically roll motion, pitching motion, yaw motion) of the vehicle 10 are selected. the distribution torque ΔT adding distributed relative to the reference torque T ₀ for each, and the distribution torque ΔT relative to the reference torque T ₀ for each of the remaining two motors subtracted allocation and limits the distribution torque ΔT according to each motor be able to.

Regarding the roll motion control in the vehicle 10, for example, as shown in FIG. 6, the motor 20 of the right front wheel 12 and the motor of the left rear wheel 13 according to information (first motion information) related to the roll motion of the vehicle 10. 21 adds allocate distribution torque [Delta] T relative to the reference torque T ₀ for, and to the reference torque T ₀ for motor 22 of the motor 19 and the right rear wheel 14 of the left front wheel 11 can be subtracted allocating distribution torque [Delta] T. As for pitching motion control in the vehicle 10, for example, as shown in FIG. 7, the motor 21 and the right rear wheel of the left rear wheel 13 according to the information (first motion information) related to the pitching motion of the vehicle 10. The distribution torque ΔT can be added to the reference torque T ₀ for the 14 motors 22 and the distribution torque ΔT can be subtracted from the reference torque T ₀ for the motor 19 of the left front wheel 11 and the motor 20 of the right front wheel 12. . For yaw motion control in the vehicle 10, for example, as shown in FIG. 8, the motor 20 and the right rear wheel 14 of the right front wheel 12 according to information (second motion information) related to the yaw motion of the vehicle 10. The distribution torque ΔT can be added and distributed to the reference torque T ₀ for the motor 22, and the distribution torque ΔT can be subtracted from the reference torque T ₀ for the motor 19 for the left front wheel 11 and the motor 21 for the left rear wheel 13. .

  Furthermore, it is preferable to provide a priority for limiting the distribution torque in the distribution torque limit mode according to the state of the driving motion of the vehicle 10 described above. For example, it is preferable that the distributed torque limit mode is selected when the roll motion control or the pitching motion control is executed, while the distributed torque limit mode is not selected when the yaw motion control is executed. In short, regarding the priority for limiting the distribution torque, the pitching motion control or the roll motion control related to the ride comfort of the vehicle occupant is more important than the yaw motion control related to the steering stability of the vehicle 10. It is set to be higher. Thereby, while sacrificing the ride comfort of the occupant of the vehicle, it is possible to appropriately control the vehicle movement so as not to impair the steering stability of the vehicle 10 as much as possible, and to suppress an increase in power consumption related to the control. become.

  In the above embodiment, a four-wheel motor vehicle or a two-wheel motor vehicle has been described. However, the number of wheels and the number of a plurality of motors that independently drive the wheels are not limited. It can be changed accordingly. In this case, the distribution torque can be limited for all or some of the plurality of motors.

  When based on description of said embodiment and various modifications, this invention can take the following each aspects (aspect).

In the present invention,
“Wheel control method according to claim 10,
In the distributed torque limit mode, when the magnitude of at least one of the first distributed torque and the second distributed torque exceeds the reference torque, the magnitude of the distributed torque is the reference torque. A wheel control method for restricting a change in the direction of operation of the torque for each of the first motor and the second motor by limiting the distribution torque so as to be equal to or less than the magnitude of the torque. "
The mode (mode 1) can be taken.

In the present invention,
“Wheel control method according to aspect 1,
In the distributed torque limit mode, when the magnitude of at least one of the first distributed torque and the second distributed torque exceeds the reference torque, the magnitude of the distributed torque is the reference torque. A wheel control method for preventing a change in the direction of torque acting on each of the first motor and the second motor by limiting the distribution torque so as to coincide with the magnitude of the torque. "
(Mode 2) can be adopted.

In the present invention,
“Claim 10, a wheel control method according to any one of aspects 1 and 2,
The plurality of motors are incorporated into one of the left wheel and the right wheel corresponding to each other of the plurality of wheels, and the other one of the left wheel and the right wheel. Constituted by only one second motor,
The wheel control method, wherein the first distribution torque related to one first motor and the second distribution torque related to one second motor are set to have the same magnitude. "
(Mode 3) can be adopted.

In the present invention,
“Claim 10, a wheel control method according to any one of aspects 1 and 2,
The plurality of motors are incorporated in each of the two first motors incorporated in two of the four wheels as the plurality of wheels, and in each of two wheels other than the two wheels. Constituted by only the second motor,
The wheel control method, wherein the first distribution torque for each of the two first motors and the second distribution torque for each of the two second motors are set to the same magnitude. "
(Aspect 4) can be taken.

In the present invention,
“Wheel control method according to aspect 4,
The second information includes first motion information related to the rolling motion or pitching motion of the vehicle, and second motion information related to the yaw motion of the vehicle,
Roll motion control or pitching motion control for setting the first distributed torque and the second distributed torque in accordance with the first motion information, and the first distributed torque and in accordance with the second motion information One of the yaw motion control for setting the second distribution torque and the control for selectively performing the roll motion control or the pitching motion control are selectively executed. On the other hand, the wheel control method does not select the distributed torque limit mode when executing the yaw motion control. "
(Embodiment 5) can be adopted.

In the present invention,
“Claim 10, a wheel control method according to any one of aspects 1 to 5,
A wheel control method in which, in the distributed torque limiting mode, when it is not necessary to reduce power consumption in the plurality of motors, the first distributed torque and the second distributed torque are not limited. "
(Aspect 6) can be adopted.

In the present invention,
“Wheel control method according to aspect 6,
When the ratio of the remaining charge with respect to the storage capacity at the time of full charge of a power storage device mounted on the vehicle as a drive source of the plurality of motors exceeds a predetermined threshold, power consumption is reduced in the plurality of motors. A wheel control method for determining that it is unnecessary. "
(Aspect 7).

Claims (10)

A wheel control device for controlling a plurality of wheels provided in a vehicle,
A control unit that performs torque control of a plurality of motors capable of independently driving the plurality of wheels;
The control unit sets a predetermined reference torque for each of the plurality of motors in accordance with first information relating to an input operation by a driver, and the reference torque in accordance with second information relating to a motion state of the vehicle. Is a torque obtained by controlling one or a plurality of first motors of the plurality of motors with a torque to which a first distribution torque is added and distributed, and a torque obtained by subtracting a second distribution torque from the reference torque. Controls one or a plurality of second motors different from the first motor, and the direction of torque does not change before and after the addition distribution and the subtraction distribution for each of the first motor and the second motor. As described above, the wheel control device includes a distributed torque limiting mode in which the first distributed torque and the second distributed torque are limited. The wheel control device according to claim 1,
In the distributed torque limit mode, the control unit determines the distribution torque when the distribution torque of at least one of the first distribution torque and the second distribution torque exceeds the reference torque. A wheel control device that prevents a change in the direction of operation of torque for each of the first motor and the second motor by limiting the distribution torque so that the magnitude is equal to or less than the magnitude of the reference torque. The wheel control device according to claim 2,
In the distributed torque limit mode, the control unit determines the distribution torque when the distribution torque of at least one of the first distribution torque and the second distribution torque exceeds the reference torque. A wheel control device that prevents a change in the direction of torque acting on each of the first motor and the second motor by limiting the distribution torque so that the magnitude matches the magnitude of the reference torque. The wheel control device according to any one of claims 1 to 3,
Wherein the plurality of motors, one of said first motor incorporated in either one of the left wheel and the right wheel corresponding to each other among the plurality of wheels, one of which incorporated into the other of said left wheel and said right wheel Constituted only by the second motor,
The said control part is a wheel control apparatus which sets the said 1st distribution torque regarding one said 1st motor, and the said 2nd distribution torque regarding one said 2nd motor to the same magnitude | size. The wheel control device according to any one of claims 1 to 3,
The plurality of motors are incorporated in each of the two first motors incorporated in two of the four wheels as the plurality of wheels, and in each of two wheels other than the two wheels. Constituted by only the second motor,
The control unit sets the first distribution torque for each of the two first motors and the second distribution torque for each of the two second motors to the same magnitude. . The wheel control device according to claim 5,
The second information includes first motion information related to the rolling motion or pitching motion of the vehicle, and second motion information related to the yaw motion of the vehicle,
The control unit controls the roll motion control or the pitching motion control for setting the first distribution torque and the second distribution torque according to the first motion information, and the first motion information according to the second motion information. One of the yaw motion control for setting the 1 distributed torque and the second distributed torque is selectively executed, and the roll motion control or the pitching motion control is performed when the roll motion control or the pitching motion control is performed. A wheel control device that selects a distributed torque limiting mode, but does not select the distributed torque limiting mode when executing the yaw motion control. The wheel control device according to any one of claims 1 to 6,
In the distributed torque limiting mode, the control unit does not limit the first distributed torque and the second distributed torque when it is not necessary to reduce power consumption in the plurality of motors. The wheel control device according to claim 7,
In the plurality of motors, when the ratio of the remaining charge with respect to the storage capacity at the time of full charge of a power storage device mounted on the vehicle as a drive source of the plurality of motors exceeds a predetermined threshold, A wheel control device that determines that reduction in power consumption is unnecessary. Multiple wheels,
A plurality of motors capable of independently driving each of the plurality of wheels;
A motor control device for controlling the plurality of motors;
Including
The said motor control apparatus is a vehicle comprised by the wheel control apparatus as described in any one of Claims 1-8. A wheel control method for controlling a plurality of wheels provided in a vehicle,
For torque control of a plurality of motors capable of independently driving the plurality of wheels, a step of setting a predetermined reference torque for each of the plurality of motors according to first information related to an input operation by a driver; Controlling one or a plurality of first motors of the plurality of motors with a torque obtained by adding and distributing a first distribution torque to the reference torque according to second information relating to the motion state of the vehicle; and One or a plurality of second motors different from the first motor are controlled with a torque obtained by subtracting and distributing the second distribution torque from the reference torque, and the torque of each of the first motor and the second motor is controlled. A distribution torque limit in which the first distribution torque and the second distribution torque are limited so that the action direction of the first distribution torque does not change before and after the addition distribution and the subtraction distribution Including the step of using the over-de, wheel control method.

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